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 * Licensed to the Apache Software Foundation (ASF) under one   *
 * or more contributor license agreements.  See the NOTICE file *
 * distributed with this work for additional information        *
 * regarding copyright ownership.  The ASF licenses this file   *
 * to you under the Apache License, Version 2.0 (the            *
 * "License"); you may not use this file except in compliance   *
 * with the License.  You may obtain a copy of the License at   *
 *                                                              *
 *   http://www.apache.org/licenses/LICENSE-2.0                 *
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 * Unless required by applicable law or agreed to in writing,   *
 * software distributed under the License is distributed on an  *
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
 * KIND, either express or implied.  See the License for the    *
 * specific language governing permissions and limitations      *
 * under the License.                                           *
 ****************************************************************/

package org.apache.hupa.server.ioc;

import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import javax.servlet.ServletContextEvent;

import org.apache.commons.logging.Log;
import org.apache.hupa.server.ioc.demo.DemoGuiceServerModule;
import org.apache.hupa.server.utils.ConfigurationProperties;

import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.Module;
import com.google.inject.servlet.GuiceServletContextListener;

public class GuiceListener extends GuiceServletContextListener {

	public static final String SYS_PROP_CONFIG_FILE = "hupa.config.file";
	public static final String CONFIG_FILE_NAME = "config.properties";
	public static final String CONFIG_DIR_IN_WAR = "WEB-INF/conf/";

	private String servletContextRealPath = "";

	private Properties demoProperties = null;
	private String demoHostName = null;

	@Override
	public void contextInitialized(ServletContextEvent servletContextEvent) {
		servletContextRealPath = servletContextEvent.getServletContext().getRealPath("/");

		// We get the mock classes using reflection, so as we can package Hupa
		// without mock stuff.
		try {
			Class<?> mockConstants = Class.forName("org.apache.hupa.server.mock.MockConstants");
			demoProperties = (Properties) mockConstants.getField("mockProperties").get(null);
			demoHostName = demoProperties.getProperty("IMAPServerAddress");
		} catch (Exception noDemoAvailable) {
		}

		super.contextInitialized(servletContextEvent);
	}

	@Override
	protected Injector getInjector() {

		Properties prop = loadProperties();
		ConfigurationProperties.validateProperties(prop);

		boolean demo = prop.getProperty("IMAPServerAddress").equals(demoHostName);
		Module module = demo ? new DemoGuiceServerModule(prop) : new GuiceServerModule(prop);

		Injector injector = Guice.createInjector(module, new GuiceWebModule());

		String msg = ">> Started HUPA ";
		if (demo) {
			msg += "in DEMO-MODE";
		} else {
			msg += "with configuration -> " + prop;
		}
		injector.getInstance(Log.class).info(msg);
		return injector;
	}

	/**
	 * Loads the first available configuration file.
	 * 
	 * The preference order for the file is: 1.- file specified in a system
	 * property (-Dhupa.config.file=full_path_to_file) 2.- file in the user's
	 * home: $HOME/.hupa/config.properties 3.- global configuration in the os:
	 * /etc/default/hupa 4.- file provided in the .war distribution:
	 * "WEB-INF/conf/config.properties 5.- mock properties file which makes the
	 * Hupa work in demo mode.
	 * 
	 * If the system property "mock-host" has been defined, and Hupa has been
	 * packaged with the mock stuff, we always return the demo-mode
	 * configuration.
	 * 
	 */
	public Properties loadProperties() {
		Properties properties = null;
		if (demoHostName == null || System.getProperty(demoHostName) == null) {
			List<String> configurationList = new ArrayList<String>();
			configurationList.add(System.getProperty(SYS_PROP_CONFIG_FILE));
			configurationList.add(System.getenv("HOME") + "/.hupa/" + CONFIG_FILE_NAME);
			configurationList.add("/etc/default/hupa");
			configurationList.add(servletContextRealPath + "/" + CONFIG_DIR_IN_WAR + CONFIG_FILE_NAME);

			for (String name : configurationList) {
				properties = ConfigurationProperties.loadProperties(name);
				if (properties != null) {
					break;
				}
			}
		}
		return properties == null ? demoProperties : properties;
	}
}
